2. show the phone number/numbers only on a specific page , and measure conversions to that page. this is a reasonable approximation for calls,
more complex: google "call tracking" , many providers offer tools.
Will look into call tracking, thanks!
The company is called Yext, and from what I remember at that time, there was concern about Yext placing phone numbers that they control across the web for the local businesses that they service; the implication being that there is some lock-in, and possibly some web juice being lost.
EDIT: I decided to actually check out the site and they assign only one number, so no a/b testing. I searched, but found no pricing, so it looks like they are discriminating based on the specific type of business.
It was interesting they made note that people tend to call local numbers more regularly than 800 or out of state, so I guess that is a feature to look for.